1. Field of the Invention
The present invention relates to a readout controlling apparatus, player, and recorder of a digital disk or other recording media and a readout controlling method.
2. Description of the Related Art
When playing back a digital versatile disk (DVD), a DVD player etc. converts an analog signal read from the DVD to a digital signal and applies 8 to 16 demodulation to the digital signal. It then stores one error correcting code (ECC) block's worth of the digital signal obtained by the 8 to 16 demodulation in a buffer memory, then reads this out, corrects its errors, and decodes the error corrected digital signal.
Here, the error correction is performed in units of ECC blocks on the digital signal read from the DVD.
FIG. 1 is a view for explaining the format of an ECC block.
BM,N (0≦M≦192, 0≦N≦171) shown in FIG. 1 is information data composed of 16 sectors each comprised by 172 bytes times 12 rows.
BM,N (0≦M≦207, 172≦N≦181) is an inner code parity of the Reed-Solomon code.
Namely, the inner code parity BM,N (172≦N≦181) is an inner code parity of the information data BM,N (0≦N≦171).
Also, BM,N (192≦M≦207, 0≦N≦171) is an outer code parity of the Reed-Solomon code.
Namely, the outer code parity BM,N (192≦M≦207) is an outer code parity of the information data BM,N (0≦M≦192).
In the above error correction, outer code error correction is performed in units of code blocks corresponding to the columns shown in FIG. 1, while inner code error correction is performed in units of code blocks corresponding to the rows shown in FIG. 1.
In this case, in error correction performed in units of code blocks, the number of bytes able to be corrected for error is determined in accordance with the number of bytes of the parity.
Accordingly, when the playback condition of a DVD is poor and more than a predetermined number of bytes include error, there is a disadvantage that there are bytes unable to be corrected for error and therefore quality of a digital signal reproduced deteriorates.
Also when recording a digital signal in a DVD, if the recording condition is poor, there is a disadvantage that the quality of the digital signal recorded on the DVD deteriorates.